In prior art phase-shifting combiners, the phase shifters are constituted by lengths of transmission line or by a hybrid coupler having two access ports provided with short-circuited transmission lines.
Applications have remained very limited because of the losses or the mismatches to which they give rise.
Applications currently in use include the following:
two or four phase state modulators;
phase shifting combiners; and
waveguides having variable permeability or permitivity.
In the prior art, the manual entitled "Microwave filters, impedance matching, networks and coupling structures" by Matthaei (McGraw-Hill, 1964) pp. 872 to 887 describes a ring resonator which is a passive power multiplying device.
The object of the invention is to mitigate the drawbacks outlined above.